JPH072975B2 - Continuous annealing equipment with excellent stripability - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a continuous annealing apparatus having an excellent strip-passing property, and a strip-shaped material such as a metal strip can be continuously striped without causing meandering or buckling. The present invention relates to an annealing device.

(Prior Art) A continuous annealing furnace is generally composed of a heating zone, a soaking zone, a cooling zone or an overaging zone, in which strips are wound around a conveying roll and passed through a plate to be annealed continuously.

In continuous strip annealing, it is important to prevent buckling, which is referred to as meandering or buckling, in strip passing in order to secure good quality and shape or to improve productivity.

Conventionally, as a technique for preventing meandering and buckling in continuous annealing, a conveyor roll having a variable crown is provided to change the crown during the operation of the continuous annealing furnace, for example, JP-A-55-100919, It is proposed in Japanese Patent Publication No. Sho 57-137431.

(Problems to be Solved by the Invention) By the way, the strip to be continuously annealed has a thin plate thickness, a narrow strip width to a wide strip, and a soft strip.
There are various types such as hard ones. Among these, particularly thin and wide strips have a narrow range that satisfies the centering force required to correct the meandering and the crown amount that must not be exceeded to prevent buckling. Extremely difficult to do. For example, when the strip running speed suddenly changes due to the necessity of operation or the size of the strip to be stripped changes, both buckling and meandering cannot be completely prevented.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a continuous annealing device having excellent stripability, which enables stable stripping without causing buckling and meandering even with a thin, wide and soft strip. .

(Means for Solving Problems) Hereinafter, the present invention will be described in detail with reference to the drawings based on an embodiment.

The present inventors have conducted various experiments and studies in order to enhance the sheet passing property. As a result, it was confirmed by mechanical analysis that the centering force depends on the crown amount θ of the transport roll 1 and the width B of the strip 2 in contact with the crown portion of the roll, as shown in FIG. That is, it has been found that by controlling the shape of the strip, if the width of the strip contacting the crown of the transport roll is maintained at an appropriate value, it is possible to pass the strip without causing buckling or meandering.

As a device configuration for embodying this, a device for applying thermal strain to the strip is provided on the inlet side or outlet side of the transport roll provided in the continuous annealing furnace or the continuous plating furnace, or both the inlet side and the outlet side.

FIG. 1 schematically shows a carrier roll 1 and a strip 2 in a vertical continuous annealing furnace, and shows an embodiment of the present invention in which a heat distortion imparting device 3 is provided on the carrier roll at the upper part of the furnace. The strip 2 is wound around the transport roll 1 and passed through in the arrow direction.

In the present invention, when the strip 2 is wound around the transport roll 1, the thermal strain imparting device 3 installed immediately before, immediately before, or immediately after the strip 2 applies a heating or cooling action to the strip 2 to cause thermal strain, and thus the transport roll 1 is heated. Make the width of the strip in contact with the crown proper.

The thermal strain imparting device 3 will be described with reference to FIG. The thermal strain imparting device 3 is provided separately in the width direction of the strip 2. For example, a heating device 3-1 is used as the thermal strain imparting device 3 as shown in FIG. As in (B), a combination of the heating device 3-1 and the cooling device 3-2 is used, or although not shown, only the cooling device is used. These heating device 3-1 and cooling device 3-2
Respectively independently apply a heating action or a cooling action to the strip, impart a thermal strain to the strip 2, and make its shape suitable for a strip.

For example, when meandering occurs between the transport rolls in the preceding stage while passing the strip through the strip, the heating device 3-1 applies a heating action to the central portion of the width of the strip 2 and the vicinity thereof so that the medium stretched shape 4 Then, the width of the strip 2 in contact with the crown portion of the transport roll is widened to increase the centering force. On the contrary, when buckling is likely to occur, both ends of the strip 2 are heated in order to prevent it, or the central part of the strip 2 is cooled to make the strip shape end-extended shape 5 and the conveyance roll 1 The width of the strip 2 in contact with the crown portion may be narrowed to reduce the centering force.

(Example) Next, an example will be described.

The thermal strain imparting device 3 according to the present invention is arranged from the latter part of the heating zone of the vertical continuous annealing furnace to the soaking zone, and the conveying roll 1 has a diameter of 800 m.
A low carbon steel sheet having a thickness of 0.3 mm and a width of 1200 mm as strip 2 with m and a crown size tan θ = 0.001 was annealed at a striping speed of 400 m / min at a recrystallization temperature or higher. By making the temperature distribution in the width direction of the strip 2 high at both ends, it was possible to pass the strip without buckling or meandering.

(Effects of the Invention) As described above, by applying thermal strain to the strip contacting the transport roll according to the present invention, a stable threading without buckling or meandering is possible. It is particularly effective when applied to continuous annealing of thin, wide and soft steel plates.

[Brief description of drawings]

FIG. 1 is an explanatory view showing an embodiment of a continuous annealing apparatus of the present invention, FIG. 2 is a view showing an embodiment of an apparatus for applying thermal strain to a strip, and FIG. FIG. 4 and FIG. 4 are views for showing an example of middle elongation and edge elongation which occur in the strip.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazuyuki Tashiro 1-1-1 Edamitsu, Yawatahigashi-ku, Kitakyushu, Fukuoka Prefecture Inside the Hachiman Works, Nippon Steel Co., Ltd. 1-1-1 Kueda Mitsue 1-1 Hachiman Works, Nippon Steel Co., Ltd. (56) References JP 59-80734 (JP, A) JP 59-157226 (JP, A)

Claims (1)

[Claims] 1. An apparatus for continuously annealing a belt-shaped material by passing the belt-shaped material over a conveying roll and continuously annealing the belt at the inlet side or outlet side, or both the inlet side and outlet side of the conveyor roll. A continuous annealing device with excellent plateability, which is equipped with a device that can be adjusted in the direction.